The proposed research is aimed at investigating psychological mediators of institutional adaptation of the aged. It is hypothesized that the effects of stressful life experiences such as institutionalization are mediated by the perceived predictability and controllability of the institutional environment. Two completed experimental field studies demonstrate that (a) a positive predictable or controllable event has a significant positive impact on the psychological and physical well-being of the instutionalized aged and (b) increasing the predictability of an institutional environment can significantly improve the psychological and physical well-being of new admissions. In addition, it was found that persons who are initially more aggressive, extroverted, and who feel they have personal control as measured by personality scales, and more in need of and benefit most from predictability and control enhancing interventions. Studies in progress are designed to answer questions on the relationship between feelings of competence and control and their effect on health and psychological status. Two additional studies are planned examining the relationship between control over information and health status, and the effect of having control over the physical environment on physical and psychological well-being. Both short and long term effects of control enhancing interventions are being examined in all studies. In addition, a large variety of individual difference variables are examined as possible predictors of adaptation to institutions in general. To the extent that interventions undertaken in the proposed research prove effective, new procedures useful in the treatment of the hospitalized aged will have been indicted. Moreover, psychological mechanisms capable of mediating the psychological and physical well-being of the aged will have been identified.